Some wind power generation devices similar to the above described wind power generation device have been proposed in view of efficient rotation of an impeller for improving power generation efficiency (see Japanese Utility Model Laid-Open No. 56-74871).
The inventor of the present application has studied airflow near a wind power generation device and found that power generation efficiency is susceptible to improvement.
Thus, the present invention has an object to provide a wind power generation device capable of improving power generation efficiency.